There is an increasing demand in recent years for an in-vehicle moving image recording apparatus, called a drive recorder, also called an event data recorder which records the surrounding circumstances of a travelling vehicle to analyze an accident cause and recognize driving habits and tendency so that the analysis and information can be used for safe driving guidance. The in-vehicle moving image recording apparatus, which was initially developed for use in commercial vehicles such as taxis and large trucks, is now increasingly used in private cars as well.
The in-vehicle moving image recording apparatus often records moving image data with low image quality so that the data can be recorded as long as possible in a storage memory having a limited capacity. To look into the local circumstances of an accident and analyze what caused the accident, moving image data used for the purpose should have a high image quality to better analyze the accident cause.
A known conventional in-vehicle moving image recording apparatus is provided with a vehicle speed sensor to record moving image data with a higher image quality as a vehicle speed is higher (for example, see the Patent Document 1). Another known conventional in-vehicle moving image recording apparatus is provided with a vehicle proximity estimation device wherein a frame rate used to compress moving image data which is generally low is changed to a high frame rate in the event that another vehicle is approaching too close to the vehicle (for example, see the Patent Document 2).